This invention relates to a ghost canceler with an adaptive transversal filter which can be used in various television and video systems.
A known broadcast television signal has a ghost cancel reference signal which is generally shortened to a GCR signal. There are ghost cancelers designed to operate on such a television signal. In general, the ghost cancelers are used in television receivers. A ghost canceler in a television receiver detects a ghost in the received television signal by use of the GCR signal, and removes the ghost from the television signal in response to the detection of the ghost. The details of a GCR signal are explained in many documents such as Japanese Magazine "Nikkei Electronics", 1989 8.7 (No. 479), page 121, and Japanese Magazine "House Gijyutsu", April 1989.
It is know how to use an adaptive transversal digital filter in a ghost canceler. In a conventional ghost canceler using an adaptive transversal digital filter, a ghost cancel reference signal is extracted from an input video signal in response to a reference signal extracting pulse, and the filtering characteristic of the filter is determined on the basis of the extracted reference signal. The conventional ghost canceler tends to be adversely affected by a jitter of the reference signal extracting pulse and also a sudden error contaminating the reference signal.
Useful background information is described in Japanese Magazine "Radio Gijyutsu", December 1989, pages 188-192.